Electrically active defects in Ta-doped β-Ga2O3 grown using the optical floating zone method

Deep-level defects in Ta-doped β-Ga2O3 single crystals grown using the optical floating zone method are investigated. Deep-level transient spectroscopy (DLTS) in conjunction with Laplace-DLTS (L-DLTS) and photoluminescence (PL) has been applied to (100) oriented β-Ga2O3:Ta bulk crystals. The tempera...

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Main Authors: Christopher A. Dawe, Lijie Sun, Ananthu Vijayan V. L., Vladimir P. Markevich, Janet Jacobs, Ian D. Hawkins, Matthew P. Halsall, Anthony R. Peaker, David J. Binks, Sai Charan Vanjari, Moorthy Babu Sridharan, Martin Kuball
Format: Article
Language:English
Published: AIP Publishing LLC 2025-04-01
Series:APL Materials
Online Access:http://dx.doi.org/10.1063/5.0261495
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Summary:Deep-level defects in Ta-doped β-Ga2O3 single crystals grown using the optical floating zone method are investigated. Deep-level transient spectroscopy (DLTS) in conjunction with Laplace-DLTS (L-DLTS) and photoluminescence (PL) has been applied to (100) oriented β-Ga2O3:Ta bulk crystals. The temperature dependence of the bias capacitance of diodes indicates no significant sign of carrier freeze-out down to 20 K. This confirms the predicted shallow donor behavior of Ta impurity atoms in β-Ga2O3 samples with a carrier concentration of (1.0–1.2) × 1018 cm−3. DLTS and L-DLTS analysis show six traps with activation energies of electron emission of 0.28 (Es), 0.46 (E9), 0.52 (E1), 0.69 (E2a), 0.75 (E2b), and 0.97 (E3) eV, with trap concentrations in the range of 1015–1017 cm−3. In addition, temperature-dependent PL has been used to study the broad luminescence bands with their maxima at 3.10 and 3.40 eV. Subsequent Arrhenius analysis extracted activation energy values (EA of 20 ± 1 and 79 ± 4 meV for quenching of the PL peaks at 3.10 and 3.40 eV, respectively.
ISSN:2166-532X